Since mid-December, weekly coronavirus cases have fallen sharply across the state, week in and week out.

That trend reversed this week, but slightly.

On Friday afternoon, the state and its seven health districts reported 171,039 confirmed or probable coronavirus cases, a 1.1 percent increase from last week.

The slight uptick in cases was hardly across the board.

Four counties — Ada, Canyon, Kootenai and Bonneville — accounted for more than half of the new cases.

Infection rates increased in several large counties, with sharp increases in Bonneville and Madison counties, and a slight increase in Ada County.

But across wide swaths of the state, case numbers were flat. Half of the state’s 44 cases reported fewer than 10 new cases; Camas, Clark and Washington counties reported no new cases.

Other key metrics were mixed. Deaths increased slightly, but new hospitalizations decreased and the state’s positive test rate continued its sharp decline. Vaccination numbers decreased slightly.

In other coronavirus headlines from the week:

A new vaccine on the way. On Friday, a Food and Drug Administration panel has recommended authorizing Johnson & Johnson’s coronavirus vaccine. How would a third vaccine affect the rollout in Idaho? State officials have said this new, single-dose vaccine could reach Idaho as early as next week.

In-person learning update. Idaho Falls will join several other large school districts on March 8, as it makes the transition back to full-time, face-to-face instruction. (Click here for the latest on school reopenings.)

Spring school tests. On Monday, the Biden administration said it will expect states to administer standardized tests this year. States can offer shorter tests and online assessments, and they can give the tests in the summer or fall. In addition, schools won’t be held accountable for the test scores.

Here are this week’s numbers, and comparisons with the previous week:

Weekly positive test rate, as reported by the state: 5.1 percent for week ending Feb. 20, down from 5.4 percent the previous week.